available online at http://meteoritics.org 1287 © Meteoritical Society, 2004. Printed in USA. The activity of chromite in multicomponent spinels: Implications for T-fO2 conditions of equilibrated H chondrites Ronit KESSEL,1* John R. BECKETT,1 Gary R. HUSS,2 and Edward M. STOLPER1 1Institute of Earth Sciences, The Hebrew University, Givat-Ra, Jerusalem, 91904, Israel 2Department of Geological Sc...

The individual isotopes of neon in energetic solar flare particles have been clearly resolved with arms mass resolution of 0.20 amu. We find 20Ne/22Ne = 7.6 ( +2.0, -1.8) and 21Ne/22Ne < 0.11 in the 11-26 MeV per nucleon interval. This isotopic composition is essentially the same as that of meteoritic planetary neon-A and is significantly different from that of the solar wind. Subject headings:...

Solutions with as little as 1% enantiomeric excess (ee) of D- or L-phenylalanine are amplified to 90% ee (a 95/5 ratio) by two successive evaporations to precipitate the racemate. Such a process on the prebiotic earth could lead to a mechanism by which meteoritic chiral alpha-alkyl amino acids could form solutions with high ee values that were needed for the beginning of biology.

PRESOLAR XENON COMPONENTS IN METEORITIC NANODIAMONDS. J. D. Gilmour 1 , G. Holland 1 , G. Turner 1 , A. B. Verchovsky 2 , A. V. Fisenko 3 and L. F. Semjonova 3 . 1 School or Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK, 2 Planetary and Space Sciences Research Institute, Open University, Walton Hall, Milton Keynes MK7 6AA, Bucks, U. K. 3 Vernads...

This is a very interesting paper that presents nice results on the detection of solid particles in the stratosphere. We have two short comments: 1) Page 15 line 19 (part 4.1;7 Soot): the author proposed possible sources for soot particles in the stratosphere. The (transient) presence of soot in the middle stratosphere and their possible origins, including meteoritic material, were also obtained...

Impact ejected rocks are targets for life detection missions to Mars. The Martian subsurface is more favourable to organic preservation than the surface owing to an attenuation of radiation and physical separation from oxidising materials with increasing depth. Impact events bring materials to the surface where they may be accessed without complicated drilling procedures. On Earth, different as...

Controversy continues as to whether chloromethane (CH3Cl) detected during pyrolysis of Martian soils by the Viking and Curiosity Mars landers is indicative of organic matter indigenous to Mars. Here we demonstrate CH3Cl release (up to 8 μg/g) during low temperature (150-400°C) pyrolysis of the carbonaceous chondrite Murchison with chloride or perchlorate as chlorine source and confirm unequivoc...

The isotope ratio, Rb/Rb, places constraints on models of the nucleosynthesis of heavy elements, but there is no precise determination of the ratio for material beyond the Solar System. We report the first measurement of the interstellar Rb isotope ratio. Our measurement of the Rb I line at 7800 Å for the diffuse gas toward ρ Oph A yields a value of 1.21 ± 0.30 (1-σ) that differs significantly ...

Solar photospheric and meteoritic CI chondrite abundance determinations for all elements are summarized and the best currently available photospheric abundances are selected. The meteoritic and solar abundances of a few elements (e.g., noble gases, beryllium, boron, phosphorous, sulfur) are discussed in detail. The photospheric abundances give mass fractions of hydrogen (X 1⁄4 0:7491), helium (...

Life on Mars, if it exists, may share a common ancestry with life on Earth derived from meteoritic transfer of microbes between the planets. One means to test this hypothesis is to isolate, detect, and sequence nucleic acids in situ on Mars, then search for similarities to known common features of life on Earth. Such an instrument would require biological and chemical components, such as polyme...